Apparatus for electrically stunning animals prior to slaughtering



R. W. RAINS April 16, 1968 PRIOR TO SLAUGHTERING ll Sheets-Sheet 1 FiledMarch 6, 1967 INVENTOR fizcdrd 13 2.67.21;

3 lv 4 w JP M T1 I 1 n w v M iv F -WMRK Aprzl 16, 1968 R. W. RAINSAPPARATUS FOR ELECTRICALLY STUNNING ANIMALS PRIOR TO SLAUGHTERING FiledMarch 6, 1967 ll Sheets-Sheet :3

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AGENT Aprll 16, 1968 R. W. RAINS 3,377,649

APPARATUS FOR ELECTRICALLY STUNNING ANIMALS PRIOR TO SLAUGHTERING FiledMarch 6, 1967 ll Sheets-Sheet 4 1/445 iii/1771 6 LEI izz AGENT April 16,1968 R. w. RAINS 3,377,649

AFPARATUS FOR ELECTRICALLY STUNNING ANIMALS PRIOR TO SLAUGHTERING FiledMarch 6, 1967 11 Sheets-Sheet AGENT April 16, 1968 R. w. RAINS 3,377,649

APPARATUS FOR ELEGTRICALLY STUNNING ANIMALS Y PRIOR TO SLAUGHTERINGFiled March 6, 1967 ll Sheets-Sheet 10 INVENTOR Zzahrd M41225 BYMQQ HAGENT United States Patent APPARATUS FOR ELECTRKCALLY STUNNING ANIMALSPRIOR TO SLAUGHTERlNG Richard W. Rains, Monlrton, Md, assignor toSchluderherg-Knrdle Co., Inc, Baltimore, Md, a corporation of MarylandFiled Mar. 6, 1967, Ser. No. 620,810 Claims. (Cl. 17--1) ABSTRACT OF THEDISQLOSURE An apparatus for delivering successive animals to aslaughtering station, and for the electrically stunning thereof byapplying a relatively low tranquilizing voltage thereto for anindefinite length of time, and then gradually increasing the lowtranquilizing voltage to a relatively high stunning voltage which ismaintained for a predetermined length of time and then gradually reducedand terminated.

The apparatus of the invention, which is designed for use inslaughtering houses where large numbers of animals are successivelyslaughtered, includes means by which the delivery of animals to aslaughtering station, and the stunning thereof, is controlled in timedrelation to the bleeding of successive animals at the stunning station.The apparatus is especially adapted for utilizing the method of stunninganimals which is disclosed in my copending application Ser. No. 468,696,filed July 1, 1965, now Patent No. 3,314,103, issued Apr. 18, 1967. Theinvention is shown and described herein in connection with the stunningand slaughtering of hogs, but it is equally well adapted for use in thestunning and slaughtering of cattle and sheep.

In accordance with the invention hogs are successively delivered from aloading station to a slaughtering station by a motor driven conveyorhaving the discharge end thereof disposed in position to discharge a hogtherefrom onto a receiving platform at the slaughtering station. At theslaughtering station the hogs are suspended head down from an overheadconveyor and their jugular veins out after which they are conveyed awayfrom the slaughtering station for butchering. As a hog approaches thedischarge end of the conveyor at the slaughtering station the conveyoris stopped until the slaughterer completes the slaughtering of apreviously delivered hog and is ready for the slaughtering of the nexthog.

During the dwells in the movement of the conveyor tranquilizing andstunning voltages are applied to the hog at the discharge end of theconveyor to render it unconscious so that it will be insensitive to painduring the bleeding thereof. The stunning voltages are applied to thehogs through an applicator having a pair of electrodes which are securedin longitudinally spaced relation to each other, to a body or handlemember. One elec trode is adapted for application to the head of ananimal, and the other electrode is adapted for application to the backof the animal. Thus a voltage applied to the electrodes will passbetween the electrodes through the brain and back of an animal. Thestunning voltage potential is such that it will render an animalunconscious but will not stop the heart action thereof which isessential for the proper bleeding of the animal. A relatively lowtranquilizing voltage, which soothes and pacifies an animal, is firstapplied to an animal at the discharge end of the conveyor during theentire dwell period of the conveyor while waiting for the completion ofthe slaughtering of an animal just previously delivered to theslaughtering station, and then when the slaughterer is ready for thenext animal, a stunning voltage is applied to the animal by graduallyincreasing the relatively low tranquilizing voltage to a relatively highstunning voltage which is maintained constant for a predetermined lengthof time and then gradually reduced and terminated, after which theconveyor is started to discharge the stunned animal therefrom and toadvance the next animal up to the discharge end of the conveyor. Theforegoing operation is repeated for each successive animal deliveredfrom the loading station to the slaughtering station. The successiveapplications of tranquilizing and stunning voltages to an animal areinitiated by an operator through a pair of manually actuated switcheswhich are mounted on the applicator handle. The operation of theconveyor is automatically controlled, through suitable inter-connectedmechanism, by the application of the tranquilizing and stunning voltagesto the animal in timed relation thereto. The initiation of thetranquilizing voltage effects the stopping of the conveyor, and thetermination of the application of the stunning voltage to the animaleffects the starting of the conveyor.

One of the objects of the invention is to provide an apparatus which isespecially adapted for utilizing a method of stunning animals,preparatory to the slaughtering thereof, which comprises first app-lyinga low voltage tranquilizing current thereto and then applying a highvoltage stunning current thereto, by the method disclosed and claimed inmy aforesaid copending application Ser. No. 468,696.

Another object of the invention is to provide an animal stunningapparatus, of the aforesaid character, by which a stun is obtained whichresults in a far less severe reaction by the animal thereby practically,if not entirely, eliminating convulsions and lung hemorrhaging of theanimal due to the stunning thereof.

Another object of the invention is to provide an animal stunningapparatus of the aforesaid character which can be adjusted or tuned tothe type of animals being stunned taking into account the varying size,age, and temperament thereof.

Another object of the invention is to provide an ap paratus of theaforesaid character in which the operation of a conveyor, by whichanimals are successively delivered to a slaughtering station, isautomatically controlled by and in timed relation to the application ofthe tranquilizing and stunning voltages to the animals.

Still another object of the invention is to provide an apparatus of theaforesaid character which is of simple construction and is veryefficient in operation.

Having stated the principal objects of the invention other and morespecific objects thereof will be apparent from the followingspecification and the accompanying drawings forming a part thereof inwhich:

FIGURE 1 is a diagrammatic plan view of a conventional animalslaughtering layout showing the relative arrangement of a corral, aslaughtering station and a connecting conveyor by which animals aresuccessively delivered from the corral to the slaughtering station;

FIG. 2 is a side elevation of one type of applicator through whichtranquilizing and stunning voltages are imparted to successive animalsas they are being delivered from the corral to the slaughtering station;

FIGS. 3 and 3 joined together on the lines A--A constitute adiagrammatic layout of the: entire apparatus showing the conveyor motorenergized and driving the conveyor, and the stunning mechanism in itsnormal inoperative condition;

FIGS. 4 and 4 joined together on the lines B--B constitute a viewsimilar to FIGS. 3-3 showing the conveyor motor de-energized with theconveyor stationary, and the stunning mechanism in condition to startthe gradual increase of the relatively low transquilizing voltage up tothe relatively high stunning voltage;

FIGS. 5-5 joined together on the lines C-C constitute a view similar toFIGS. 4-4 showing the condition of the stunning mechanism at thetermination of the gradual increasing of the relatively lowtransquilizing up to the relatively high stunning voltage;

FIGS. 6 and 6 joined together on the lines DD constitute a view similarto FIGS. -5 showing the stunning mechanism in condition to start thegradual reduction of the relatively high stunning voltage after it hasbeen maintained constant for the predetermined length of time; and

FIGS. 7 and 7 joined together on the lines EE constitute a view similarto FIGS. 6-6- showing the stunning mechanism, at the end of the gradualreduction of the stunning voltage, in condition to de-ener'gize thevariable voltage source, and energize the conveyor motor therebystarting the operation of the conveyor.

The general construction and arrangement of the apparatus will now bespecifically described in connection with the drawing by the use ofreference characters in which the numeral 1 indicates generally aconveyor by which animals are successively delivered from a pen orcorral 2 to a slaughtering station 3. The rear end 4 of the conveyor isdisposed within the corral 2, and the forward end 5 thereof is disposedin position to discharge animals therefrom to the slaughtering station3. At the slaughtering station the animals are suspended head down froman overhead conveyor 6 during slaughtering and are conveyed away fromthe slaughtering station thereby after bleeding.

The conveyor 1, which is of conventional construction, comprises a pairof similar spaced parallel units 7 and 8 which are driven in unison witheach other by a motor 9 through a gear box 10. The opposed inner flights11 and 12 of the conveyor units 7 and 8 are inclined downwardly andinwardly toward each other. The opposed flights 11 and 12 grip the sidesof animals being conveyed to the slaughtering station with the legs ofthe animals extending downwardly between the lower edges of the flight.

As animals approach the discharge end 5 of the conveyor, and during thetime they are held there awaiting the completion of the slaughtering ofthe animal just previously delivered to the slaughtering station, therelatively low tranquilizing voltage is applied thereto; and just priorto the discharge of the animal from the conveyor to the slaughteringstation, the relatively high stunning voltage is applied thereto.

The tranquilizing and stunning voltages are imparted to the animalsthrough an applicator 14, such as shown in FIG. 2, which is adapted tobe manually applied to the head and back of animals while they are atthe discharge end 5 of the conveyor 1. The applicator 14 comprises anelongated tubular body or handle member 15, having a straight downwardlyextending arm 16 secured thereto adjacent the rear end thereof, and aforwardly and downwardly extending arcuate arm 17 secured to the forwardend thereof. A block 18, of insulating material, is secured to the lowerend of the arm 16, and a similar block 19 of insulating material issecured to the lower end of the arm 17. An elongated cylindrical metalelectrode 20 is secured to and extends downwardly from the block 18, anda similar electrode 21 is secured to and extends downwardly from theblock 19. A pair of normally open switches 22 and 23 of the push buttontype, which are adapted to be manually momentarily actuated, are mountedin the handle member 15. A finger guard 24 is secured to the undersideof the handle member adjacent the arm 16. The electrodes and 21 areconnected to a variable voltage source by conductors which are disposedwithin the tubular handle 15 and arms 16 and 17 and extend out therefromin a cable 25. In use the electrode 20 is applied to the head of ananimal and the electrode 21 is applied to the back of the animal.Current will then flow from the voltage source to the electrode 20,thence through the brain and back of the animal to the electrode 21, andfrom there back to the voltage source,

as will be explained in detail hereinafter. The applicator 14, per se,forms no part of the present invention. Consequently, it is not beingshown and described in more detail herein.

The control mechanism, generally indicated by the numeral 30, by whichthe tranquilizing and stunning voltages are applied to animals throughthe applicator 14, and the operation of the conveyor drive motor 9 areeifected and controlled in sequentially timed relation with respect toeach other will now be described.

The mechanism 36 and the conveyor motor 9 are connected to a commercial110 v. line 31 through a pair of line conductors 32 and 33 which areconnected to the opposite sides 34 and 35 respectively of the line 31. Adouble pole master control switch 36 is interposed in the conductors 32and 33.

The motor 9 is connected between a pair of conductors 37 and 38 whichare connected to the line conductors 32 and 33 respectively. Theconductor 37 has a normally closed manually actuated switch 37interposed therein, which is preferably located at the corral or loadingstation 2, and the conductor 38 has an automatically actuated switch 39interposed therein. The switch 37 is provided so that the conveyor maybe stopped independently of the control mechanism 30.

The variable voltage source 40 of the tranquilizing and stunningvoltages, comprises a manually adjustable autotransformer 41, a magneticcore step-up isolating transformer 42, and an automatically adjustableauto-transformer 43. The terminal 44 of the winding 45 of thetransformer 41 is connected to the line conductor 32 by a conductor 46and the terminal 47 thereof is connected to the line conductor 33 by aconductor 48. The terminal 49 of the primary winding 50 of thetransformer 42 is connected to the terminal 44 of the auto-transformerwinding 45 by a conductor 51, and the terminal 52 of the winding 50 isconnected to the manually adjustable slider 53, of the auto-transformer41, by a conductor 54. The terminal 55 of the secondary winding 56 ofthe transformer 42 is connected to the terminal 57 of the winding 58 ofthe auto-transformer 43 by a conductor 59, and the terminal 60 of thewinding 56 is connected to the terminal 61 of the winding 58 by aconductor 62. The terminal 57 of the winding 58 of the auto-transformer43 is also connected to the electrode 21 by a conductor 63, and theautomatically adjustable slider 64 of the autotransformer 43 isconnected to the electrode 20 by a conductor 65. The magnetic coretransformer 42 is interposed between the auto-transformers 41 and 43 toprevent grounding of the voltage applied to an animal on the conveyorthrough the animal and the conveyor. An ammeter 66 which is interposedin the conductor 63, and a voltmeter 67 which is connected across theconductors 63 and 65, visually indicate the current output of theauto-transformer 43 during operation. The ammeter 66 and the voltmeter67 are provided to facilitate the manual adjustment of theauto-transformer 41 as desired and to monitor the operation of thestunning mechanism at all times during operation. By manually adjustingthe slider 53 along the winding 45 of the auto-transformer 41 the outputof the auto-transformer 43 may be regulated in accordance withsuccessive positions of the slider 64 along the winding 58 of thetransformer 43. The energization and de-energization of the voltagesource 40 is controlled by a switch 68 which is interposed in theconductor 46 connecting the terminal 44 of the winding 45, of theauto-transformer 41, to the conductor 32, and comprises a pair of spacedcontacts 70 and 71 and a bridging bar 72 therefor.

The switch 39 which is interposed in the conductor 38, between the motor9 and the line conductor 32, comprises a pair of spaced contacts 73 and74 and a bridging bar 75 therefor. The bridging bars 72 and 75, of theswitches 68 and 39 respectively, which are secured to the armature 76 ofa step relay 77, are so positioned thereon with respect to each otherand to their respective contacts that when the switch 39 is closed theswitch 68 will be open and, vice versa, when the switch 68 is closed theswitch 39 will be open.

The normally open push button switch 22 which is mounted on theapplicator 14 comprises a pair of spaced contacts 79 and 80 and abridging bar 81 therefor which is mounted on a plunger 82; and thenormally open push button switch 23, which is also mounted on theapplicator 14, comprises a pair of spaced contacts 83 and 84 and abridging bar 85 therefor which is mounted on a plunger 86. The contact79 0f the switch 22 is connected to the line conductor 32 by a conductor87, and the contact 80 thereof is connected to one end of the coil 88 ofthe step relay 77 by a conductor 89. The other end of coil 88 isconnected to the line conductor 33 by a conductor 90.

The slider 64 of the auto-transformer 43 is adapted to be moved back andforth along the coil 58, between the minimum and maximum voltage outputpositions of the auto-transformer 43, as shown in FIGS. 3--3 and 4-4respectively, by a reversible motor which is operatively connected tothe slider 64 as indicated at 101. The motor 100 is also adapted torotate a shaft 102 back and forth through 180 in unison with the backand forth movement of the slider 64, first clockwise as the slider 64 ismoved from minimum to maximum output position, and thencounter-clockwise as the slider 64 is moved back from maximum outputposition to minimum output position. A plurality of cams 103, 104, 105and 106 are mounted on the shaft 102 for rotation therewith.

The cam 103 is operatively associated with and is adapted to open andclose a switch 107 comprising a stationary contact arm 108 and a movablecontact arm 109 which is disposed in engagement with the periphery ofthe cam 103. The cam 104 is operatively associated with and is adaptedto open and close a switch 110 comprising a stationary contact arm 111and a movable contact arm 112 which is disposed in engagement with theperiphery of the arm 104. The cam 105 is operatively associated with andis adapted to open and close a switch 113 comprising a stationarycontact arm 114 and a movable contact arm 115 which is disposed inengagement with the periphery of the cam 105. The cam 106 is operativelyassociated with and is adapted to open and close a switch 116 comprisinga stationary contact arm 117 and a movable contact arm 118 which isdisposed in engagement with the periphery of the cam 106. The cams 103to 106 are so constructed and arranged upon the shaft 102 that they willopen and close the switches 107, 110, 113 and 116 in a predeterminedsequence with respect to each other.

A normally closed switch 121 is adapted to be momentarily opened andclosed by an adjustable timer 122 which is actuated by a motor 123. Theswitch 121 comprises a pair of spaced contacts 127 and 128 and abridging bar 129 therefor. The bridging bar 129 is mounted on a rod 130through which it is adapted to be moved into and out of engagement withthe contacts 127 and 128 by the timer 122.

A plurality of switches 131, 132, 133 and 134 are adapted to be actuatedin union by a relay 135 comprising an armature 136 and a coil 137. Theswitch 131 comprises a pair of spaced contacts 138 and 139 and abridging bar 140 therefor. The switch 132 comprises a pair of spacedcontacts 141 and 142 and a bridging bar 143 therefor. The switch 133comprises a pair of spaced contacts 144 and 145 and a bridging bar 146therefor, and the switch 134 comprises a pair of spaced contacts 147 and148 and a bridging bar 149 therefor. The bridging bars 140, 143, 146 and149 are all mounted upon the relay armature 136 and are so positionedthereon with respect to each other that the switches 132 and 133 arenormally closed, and the switches 131 and 134 are normally open.

The contact 83 of the push button switch 23 is con- 8 nected to the lineconductor 32 by the conductor 87 and a branch conductor 155, and thecontact 84 of the push button switch 23 is connected to one end of therelay coil 137 by a conductor 156. The other end of the relay coil 137is connected to the line conductor 33 by a conductor 157.

The contact 148 of the switch 134 is connected to the contact 128 of theswitch 121 by a conductor 158, and the contact 127 of the switch 121 isconnected to the line conductor 32 by a conductor 159. The contact 147of the switch 134 is connected to the conductor 156 by a branchconductor 160.

The contact 138 of the switch 131 is connected to the line conductor 32by conductor 161 and the contact 139 of the switch 131 is connected tothe stationary contact arm 116 of the switch 110 by a conductor 162, andto the stationary contact arm 108 of the switch 107 by the conductor 162and a branch conductor 163. The contact 141 of the switch 132 isconnected to the line conductor 32 by the conductor 161 and a branchconductor 164, and the contact 142 of the switch 132 is connected to themovable contact arm 115 of the switch 113 by a conductor 165. Thecontact 144 of the switch 133 is connected to the contact 148 of theswitch 134 by a jumper 166 and the contact 145 of the switch 133 isconnected to the movable contact arm 118 of the switch 116 by aconductor 167.

The reversible motor 100 is connected to the movable contact arm 112 ofthe switch 110 by a conductor 170, and to the stationary contact arm 114of the switch 113 by a conductor 171, and to the line conductor 33 by aconductor 172. The stationary contact arm 117 of the switch 116 isconnected to the upper end of the step-relay coil 88 by a conductor 173and the conductor 89. The movable contact arm 109 of the switch 107 isconnected to the motor 123 by a conductor 174-.

The construction and arrangement of the apparatus having been described,the operation thereof will now be described, it being assumed that atranquilizing voltage of 50 volts, after being applied to an animal foran indefinite length of time, is gradually increased during one andonehalf seconds to a relatively high stunning voltage of volts which ismaintained constant for one-half second, and then gradually reducedduring one second to 90 volts and then terminated.

Referring first to FIGS. 3-3 in which the switches 37 and 39 in theconveyor motor 9 circuit are shown closed, and the control switch 68 forthe variable voltage source 40, and the manually operable push buttonswitches 22 and 23 mounted on the applicator 14 are shown open. Currentis therefore flowing from the line conductor 32 to the motor 9 throughthe conductor 37 and switch 37, and from the motor 9 back to the lineconductor 33 through the conductor 38 and switch 39. The motor 9 istherefore energized and driving the conveyor 1; and the switch 68interposed in the conductor 46 between the line conductor 32 and themanually adjustable auto-transformer 41 of the variable voltage source40, being open, the variable voltage source 40 is de-energized andinoperative to produce the tranquilizing and stunning voltages.

As an animal on the conveyor 1 approaches the end 5 of the conveyor theoperator momentarily closes the push button switch 22. Current thenflows from the line conductor 32 through the conductor 87, switch 22,and conductor 89 to the coil 88 of the step-relay 77, and from the coil88 back to the line conductor 33 through the conductor 90, therebyenergizing the step-relay 77. The steprelay 77 being energized, opensthe switch 39 moving the bridging bar 75 away from the contacts 73 and74 thereof, and simultaneously closes the switch 68 by moving thebridging bar 72 into engagement with the contacts 70 and 71 thereof, asshown in FIG. 4. The opening of the switch 39 breaks the circuit to theconveyor motor 9 thereby stopping the movement of the conveyor. Theswitch 68 being closed, current flows from the line conductor 32 throughthe conductor 46 and switch 68 to the auto-transformer 41 and from theauto-transformer 41 back to the line conductor 33 through the conductor48 thereby energizing the auto-transformer 41. The auto-transformer 4-1being energized, energizes the isolating transformer 42, which in turnenergizes the auto-transformer 43. The operator then applies theapplicator 14 to the animal at the discharge end of the conveyor withthe electrodes 20 and 21 in electrical contact with the head and back ofthe animal. A tranquilizing voltage of 50 volts then flows from theslider 64, of the auto-transformer 43, through the conductor 65 to theelectrode 20, then through the brain and back of the animal to theelectrode 21 and from there back to the auto-transformer 43 through theconductor 63.

The tranquilizing voltage is maintained until the slaughtering of theanimal just previously delivered to the slaughtering station 3 has beencompleted, at which time the operator momentarily closes the push buttonswitch 23. Current will then flow from the line conductor 32 through theconductor 87 and branch conductor 155 to the contact 83 of the pushbutton switch 23, through the bridging bar 85 to the contact 84, andfrom the contact 84 through the conductor 156 to the coil 137 of therelay 135, and from the coil 137 back to the line conductor 33, therebyenergizing the relay 135. The relay 135 being energized will close thenormally open switches 131 and 134, and simultaneously open the normallyclosed switche 132 and 133 by moving the bridging bars 140, 143, 146 and149 from the position shown in FIG. 3 to the position shown in FIG. 4The switch 134- being closed, current will flow from the line conductor32 through the conductor 159, the normally closed switch 121, and theconductor 158 to the now closed switch 134, through the switch 134,branch conductor 160 and conductor 156 to the coil 137 of the relay 135,and from the coil 137 back to the line conductor 33 through theconductor 157, thereby providing a holding circuit for the relay 135after the push button switch 23 has been released and opens.

The switch 131 being closed, current will flow from the conductor 32through the conductor 161, switch 131 and conductor 162 to thestationary contact arm 111 of the normally closed cam actuated switch110, through the switch 110 and from the movable contact arm 112 of theswitch 110 through conductor 170 to the reversible motor 100, and fromthe motor 100 back to the line conductor 33 through the conductor 172,thereby energizing the motor 100.

The motor 100 being energized will, during one and one-half seconds,advance the slider 64, of the auto-transformer 43, along the Winding 58thereof from the 50 volt output position as shown in FIG. 44 to the 170volt output position as shown in FIG. 5 thereby gradually increasing therelatively low 50 volt tranquilizing voltage to the relatively high 170volt stunning voltage. Simultaneously therewith the motor 100 will,through the shaft 102, rotate the cams 103 to 106 inclusive clockwisethrough 180 from the position shown in FIG. 4-4 to the position shown inFIG. 5-5 thereby opening the switch 110 and closing the switches 107 and113. The opening of the switch 110 broke the circuit to the motor 100thereby stopping the movement of the earns 1.03 to 106 and the slider 64in the positions shown in FIG. 55. The switch 107, and the switch 131 inseries therewith being closed, current will flow from the line conductor32 through the conductor 161, switch 131, conductor 162, and branchconductor 163 to the contact arms 108 and 109 of the switch 107. Fromthe switch 107 the current flows through the conductor 174 to the timermotor 123, and from the timer mot-or 123 back to the line conductor 33through the conductor 176 thereby energizing the motor 123. The motor123 being energized will operate the timer 122 which after one-halfsecond will actuate the rod 130 to momentarily open and close the switch121 by raising the bridging bar 129 up out of engagement with thecontacts 127 and 128, as shown in dotted lines in FIG. 6-6 and then backinto engagement therewith.

Cir

will drop back from the position shown in FIG. 5 to the position shownin FIG. 6 thereby opening the switches 131 and 134 and closing theswitches 132 and 133. It-

will therefore be seen that during the half second between the openingof the switch 110 and the simultaneous closing of the switch 107, andthe momentary opening of the switch 121, that the cams 103 to .106remained stationary in the 180 position, and that the slider 68 of theautotransformer 42 remained stationary at the 170 volt output positionthereof as shown in FIGS. 5-5 and 6-6? The 170 volt stunning voltage wastherefore maintained constant during this one half second.

Referring now to FIGS. 6-6 which show the condition of the apparatusafter the switch 121 was momentarily opened and closed at the end of theone-half second dwell. The circuit to the timer motor 123 is brokensince the switch 131 is now open. Therefore the motor 12-3 and timer 122are inactive. The circuit to the motor through the switches 131 and isbroken since both of these switches are open. Therefore the motor is nolonger energized to rotate the cams 103 and 106 in a clockwise directionor to move the slider 68 further in the same direction along the winding58 of the auto-transformer "43, but the switch 113 and the switch 132are now closed. Current will therefore flow from the line conductor 32through the conductor 161, branch conductor 164, switch 132, conductor165, switch 113, and conductor 171 to the motor 100 and from the motor100 back to the line conductor 33 through the conductor 172, therebyenergizing the motor 100 to rotate the cams 103 to 106 in acounterclockwise direction, and to simultaneously move the slider 64, ofthe auto-transformer 43, back along the winding 58 thereof toward itsinitial position, thereby gradually reducing the stunning voltage downfrom 170 volts. It is to be noted that the switch 113 was closed duringthe clockwise rotation of the cams 103 to 106 prior to the opening ofthe switch 110 and the momentary opening of the switch 121, but sincethe switch 132 was then open no current was delivered thereto. It shouldalso he noted that the switch 116 was also momentarily closed during theclockwise rotation of the cams 103 to 106, but since the switch 133 wasopen at that time no current was delivered thereto.

At the end of one seconds counterclockwise rotation of the motor 100 thecams 103 to 106 have been rotated back through 120 from the positionshown in FIGS. 66 to the position shown in FIGS. 7-7, and the slider 64has been retracted along the winding 58 of the autotransformer -43 untilthe stunning voltage has been reduced from '170 volts to 90 volts. Inthis position, as shown in FIGS. 7-7 the cam 106 has closed the switch116. Current then flows from the line conductor 32 through the conductor159, switch 121 and conductor 158 to the contact 148 of the switch 134.From the contact 148 the current flows through the juniper 166 to thecontact 144 of the switch 133, thence through the switch 133 andconductor 167 to the movable contact arm 118 of the switch 116, and fromthere through the switch 116, the conductors 173 and 89 to the coil 88,of the step-relay 77, and from the coil 88 back to the line conductor 33through the conductor 90, thereby energizing the steprelay 77 to closethe switch 39 and 'open the switch 68. The opening of the switch 68de-energizes the variable voltage source 40 thereby terminating theoutput of any voltage therefrom to the electrodes 20 and 21. The closing of the switch '39 re-makes the circuit to the conveyor motor 9 whichthen starts the conveyor -1 to discharge the animal just stunned fromthe and 5 thereof to the 9 slaughtering station '3, and to advance thenext animal up to the discharge end of the conveyor in position forstunning.

During the next half second by operation of the motor 100 the cams 103to 106 are further advanced 60 counterclockwise back to their initial 0position, as shown in FIGS. 3-3 thereby opening the switch 113; and atthe same time the slider 64 of the auto-transformer 43 is furtherretracted from the 90 volts position shown in FIGS. 7-7 toits initial 50volt position shown in FIGS. 3-3. The opening of the switch 113 breaksthe circuit to and stops the operation of the motor 100 with the entireapparatus back in initial position ready for the stunning of the nextanimal being advanced by the conveyor 1 from the corral 2 to theslaughtering station 3.

From the foregoing it will be apparent to those skilled in this art thatI have provided a very effective and relatively simple apparatus foraccomplishing the objects of this invention.

It is to be understood that I am not limited to the specificconstruction shown and described herein as various modifications may bemade therein within the spirit of the invention and the scope of theappended claims.

What is claimed is:

1. An animal stunning apparatus of the character described comprising apair of electrodes which are adapted to be applied to the head and backof an animal in spaced relation to each other, a normally inoperativevariable voltage source, conductor means connected between said variablevoltage source and said electrodes, means by which said variable voltagesource is rendered operative to impart a relatively low tranquilizingvoltage through said conductor means to said electrodes, electric powermean operatively connected to said variable voltage source, means bywhich said power means is rendered operative to gradually increase saidrelatively low tranquilizing voltage to a relatively high stunningvoltage, holding means by which said relatively high stunning voltage ismaintained constant for a predetermined length of time, means by whichsaid power means is rendered operative to gradually reduce saidrelatively high voltage, and means by which said variable voltage sourceis then rendered inoperative.

2. An animal stunning apparatus of the character described comprising apair of electrodes which are adapted to be applied to the head and backof an animal in spaced relation to each other; a normally inoperativevariable voltage source which comprises an adjustable auto-transformerhaving a winding and a slider movable along said winding; conductormeans by which said variable voltage source is connected to a source ofalternating current; other conductor means by which one end of saidwinding is connected to one of said electrodes and said slider isconnected to the other of said electrodes; a reversible electric motorwhich is operatively connected to said slider; a first motor circuit bywhich one side of said motor is connected between the opposite sides ofsaid alternating current source, and through which said motor is adaptedto be energized for rotation in one direction, and a second motorcircuit by which the other side of said motor is connected between theopposite sides of said alternating current source, and through whichsaid motor is adapted to be energized for rotation in the oppositedirection; means by which said variable voltage source is renderedoperative to impart a relatively low tranquilizing voltage through saidother conductor means to said electrodes; other means by which saidmotor is rendered operative through said first motor circuit to advancesaid slider along said windin g to thereby gradually increase saidrelatively low tranquilizing voltage to a relatively high stunningvoltage; holding means by which said relatively high stunning voltage ismaintained constant for a predetermined length of time; still othermeans by which said motor is rendered operative through said secondmotor circuit to retract said slider along said winding to therebygradually reduce said relatively high stunning voltage; and voltageterminating means by which said variable voltage source is renderedinoperative.

3. An animal stunning apparatus as defined by claim 2 in which the saidmeans by which said variable voltage source is rendered operative toimpart a relatively low tranquilizing voltage to said electrodescomprises; a normally open switch which is interposed] in said conductormeans between said variable voltage source and said alternating currentsource, a step relay which is operatively connected to said switch andis operative when initially energized to close said switch and whensubsequently reenergized to open said switch, and a manually operatedswitch which is operative when momentarily closed and opened to effectthe initial energization of said step relay.

4. An animal stunning apparatus as defined by claim 3 in which the saidvoltage terminating means by which said variable voltage source isrendered inoperative comprises; a normally open cam operated switchwhich is operative when closed to effect the subsequent re-energizationof said step relay to open said normally open switch which was closed bythe initial energization of said step relay.

5. An animal stunning apparatus as defined by claim 2 in which the saidother means by which said motor is rendered operative to advance saidslider along said winding to thereby gradually increase said relativelylow tranquilizing voltage to a relatively high. stunning voltagecomprises; a normally open switch and a normally closed switchinterposed in said first motor circuit in series with each other, arelay which is operative when energized to close said normally openswitch, and a cam which is rotated by said reversible motor in unisonwith the movement of said slider and is operative to open said normallyclosed switch, a normally open manually operable switch which isoperative when momentarily closed to effect the energizing of saidrelay, said normally open switch being operative to close the said firstmotor circuit and thereby energize said motor to advance said slideralong said winding, and said normally closed switch being operative whenopened to open the said first motor circuit thereby de-energizing saidmotor and stopping the movement of said slider along said winding.

6. An animal stunning apparatus as defined by claim 2 in which the saidholding means by which the relatively high stunning voltage ismaintained constant for a predetermined length of time comprises; atimer mechanism which is rendered operative at the termination of thegradual increasing of said relatively low tranquilizing voltage up tosaid relatively high stunning voltage by the closing of a normally opencam operated switch, said timer mechanism being operative at theexpiration of said predetermined length of time to eiiect the closing ofsaid second motor circuit to initiate the rotation of said motor in theopposite direction.

7. An animal stunning apparatus of the character described comprising; aconveyor by which animals are adapted to be successively conveyed from acorral to a slaughtering station, a conveyor motor which is operativewhen energized to drive said conveyor; a pair of electrodes which areadapted to be applied to the head and back of an animal in spacedrelation to each other; a first conductor means by which said conveyormotor is connected to a source of alternating current; a normallyinoperative variable voltage source which comprises an adjustableauto-transformer having a winding and a slider movable along saidwinding; a second conductor means by which said variable voltage source:is connected to said source of alternating current; a third conductormeans by which one end of said winding is connected to one of saidelectrodes and said slider is connected to the other of said electrodes;means by which said conveyor motor is de-energized to stop the operationof said conveyor and said variable voltage source is simultaneouslyrendered operative to impart a relatively low tranquilizing voltagethrough said third conductor means to said electrodes; a reversiblemotor which is operatively connected to said slider; other means bywhich said motor is rendered operative to advance said slider along saidwinding to thereby gradually increase said relatively low tranquilizingvoltage to a relatively high stunning voltage; holding means by whichsaid relatively high stunning voltage is maintained constant for apredetermined length of time; still other means by which said motor isrendered operative to retract said slider along said winding to therebygradually reduce said relatively high stunning voltage; and voltageterminating means by which said variable voltage source is renderedinoperative and said conveyor motor is simultaneously rendered operativeto drive said conveyor.

8. An animal stunning apparatus as defined by claim 7 in which the saidmeans by which said conveyor motor is de-energized and said variablevoltage source is simultaneously rendered operative comprises; anormally closed switch which is interposed in said first conductor meansbetween said conveyor motor and said source of alternating current, anormally open switch which is interposed in said second conductor meansbetween said variable voltage source and said source of alternatingcurrent, a step relay which is operatively connected to said normallyclosed switch and to said normally open switch and is operative wheninitially energized to open said normally closed switch and tosimultaneously close said normally open switch, and a manually operableswitch which is operative when momentarily closed to eifect the initialenergization of said step relay.

9. An animal stunning apparatus as defined by claim 8 in which the saidvoltage terminating means by which said variable voltage source isrendered inoperative and said conveyor motor simultaneously renderedoperative comprises a normally open cam operated switch which isoperative when momentarily closed to effect the re-energization of saidstep relay to close the said now open normally closed switch and tosimultaneously open the now closed normally open switch.

10. An animal stunning apparatus as defined by claim 2 in which saidvariable voltage source comprises an isolating magnetic core step-uptransformer, a manually adjustable auto-transformer which is connectedto said source of alternating current and to the primary winding of saidstep-up transformer, and an automatically adjustable auto-transformerwhich is connected to the secondary winding of said step-up transformedand to said electrodes.

References Cited UNITED STATES PATENTS 3,110,925 11/1963 McMath et a1.l71 3,123,852 3/1964 Cervin 171 3,152,357 10/1964 Wemmer 17-1 3,314,1024/1967 Rains 17-l OTHER REFERENCES Schermer et al.: German ApplicationNo. 1,144,145 (1 sht. dwg., 2 pp. spec), published Feb. 21, 1963.

LUCIE I-I. LAUDENSLAGER, Primary Examiner.

